1/* Et-forest data structure implementation.
2   Copyright (C) 2002, 2003, 2004, 2005 Free Software Foundation, Inc.
3
4This program is free software; you can redistribute it and/or modify
5it under the terms of the GNU General Public License as published by
6the Free Software Foundation; either version 2 of the License, or
7(at your option) any later version.
8
9This program is distributed in the hope that it will be useful,
10but WITHOUT ANY WARRANTY; without even the implied warranty of
11MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12GNU General Public License for more details.
13
14You should have received a copy of the GNU General Public License
15along with this program; if not, write to the Free Software
16Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
17
18/* This package implements ET forest data structure. Each tree in
19   the structure maintains a tree structure and offers logarithmic time
20   for tree operations (insertion and removal of nodes and edges) and
21   poly-logarithmic time for nearest common ancestor.
22
23   ET tree stores its structure as a sequence of symbols obtained
24   by dfs(root)
25
26   dfs (node)
27   {
28     s = node;
29     for each child c of node do
30       s = concat (s, c, node);
31     return s;
32   }
33
34   For example for tree
35
36            1
37          / | \
38         2  3  4
39       / |
40      4  5
41
42   the sequence is 1 2 4 2 5 3 1 3 1 4 1.
43
44   The sequence is stored in a slightly modified splay tree.
45   In order to support various types of node values, a hashtable
46   is used to convert node values to the internal representation.  */
47
48#ifndef _ET_TREE_H
49#define _ET_TREE_H
50
51#include <ansidecl.h>
52#include <stddef.h>
53
54#ifdef __cplusplus
55extern "C" {
56#endif /* __cplusplus */
57
58/* The node representing the node in an et tree.  */
59struct et_node
60{
61  void *data;			/* The data represented by the node.  */
62
63  int dfs_num_in, dfs_num_out;	/* Number of the node in the dfs ordering.  */
64
65  struct et_node *father;	/* Father of the node.  */
66  struct et_node *son;		/* The first of the sons of the node.  */
67  struct et_node *left;
68  struct et_node *right;	/* The brothers of the node.  */
69
70  struct et_occ *rightmost_occ;	/* The rightmost occurrence.  */
71  struct et_occ *parent_occ;	/* The occurrence of the parent node.  */
72};
73
74struct et_node *et_new_tree (void *data);
75void et_free_tree (struct et_node *);
76void et_free_tree_force (struct et_node *);
77void et_free_pools (void);
78void et_set_father (struct et_node *, struct et_node *);
79void et_split (struct et_node *);
80struct et_node *et_nca (struct et_node *, struct et_node *);
81bool et_below (struct et_node *, struct et_node *);
82
83#ifdef __cplusplus
84}
85#endif /* __cplusplus */
86
87#endif /* _ET_TREE_H */
88